Paleontology is the study of the history of life on Earth. Paleontologists look at fossils, which are the ancient remains of plants, animals, and other living things. Fossils are mainly formed in two ways. In one case, animal or plant matter is replaced by rock over time, but the remains keep their original shape. In the other case, the fossil is an impression that has been made in rock. It can be a footprint, for example, or the outline of a body pressed into mud.

Paleontologists use fossil remains to understand how species evolve. The theory of evolution says that living species change over a long period of time. Paleontologists study species that still exist and also species that have gone extinct, or died out.

Fossils can give information about an animal or plant's life and environment. For example, oyster shells have one ring for every year of life. An oyster fossil can help paleontologists discover how long that oyster lived. It can also show what the environment was like around the oyster. If the climate was good, the oyster would have grown more quickly and its rings would be thicker. If the oyster struggled to survive, the rings would be thinner. Thin rings mean the environment was not healthy for oysters and similar creatures. Maybe the water was too warm or too cold for them.

Some kinds of fossils provide information about many different sorts of living things. Amber is one example. Amber is fossilized tree sap. When sticky sap dripped down a tree trunk, it has sometimes trapped small insects, and even things like frogs and lizards. Paleontologists study amber to observe these complete specimens. Amber can preserve things as delicate as dragonfly wings.

Fossils can also help show how living beings evolved over time. For example, paleontologists believe whales evolved from land animals. They reached this conclusion based on the fossils of extinct animals that are closely related to whales. These animals lived in the ocean, but still had something similar to legs. 

Subdisciplines of Paleontology

The field of paleontology has many subdisciplines. A subdiscipline is a smaller field of study within a larger subject. 

Vertebrate Paleontology

One subdiscipline of paleontology is vertebrate paleontology. It is the study of fossils of animals with backbones. Vertebrate paleontologists have discovered the skeletons of dinosaurs and many other ancient animals. They have been able to show how these animals lived and evolved.

Take the example of pterosaurs, a group of flying reptiles. One type of pterosaurQuetzalcoatlus, was one of the largest flying creatures in history. It had an 11-meter (36-foot) wingspan. That's about as long as a telephone pole.

From looking at fossils, vertebrate paleontologists figured out that pterosaurs had hollow and light bones like birds do today. This made them realize the animals could fly by flapping their wings, rather than just by gliding. Otherwise, the bones would have been too heavy for the pterosaurs to lift off.

Invertebrate Paleontology

Invertebrate paleontologists study the fossils of animals without backbones. Mollusks, corals, crabs, shrimp, sponges and worms are all examples of invertebrates. Unlike vertebrates, invertebrates do not have bones. However, they do leave behind traces of themselves. This evidence includes fossilized shells and impressions of soft body parts. It can even include tracks along the ground or ocean floor.

Invertebrate fossils are especially important to the study of past environments. For example, large groups of 200-million-year-old invertebrate marine fossils have been found in the deserts of Nevada. They tell us that parts of the state were once covered by water. 

Paleobotany

Paleobotanists study the fossils of ancient plants. These fossils can be impressions of plants left on rock surfaces. Or, they can be parts of the plants themselves that have been preserved in rock. These fossils reveal how plants have evolved. They also help scientists understand what ancient environments were like. 

Micropaleontology

Micropaleontology is the study of fossils of tiny, microscopic organisms. Micropaleontologists use powerful microscopes to study fossils smaller than four millimeters (0.16 inches).

Micropaleontologists often study fossils to better understand how Earth's climate has changed. For example, they study the shells of deep-sea microorganisms. Such creatures make their shells out of elements found in the ocean water around them. These shells tell us what the ocean was like when the creatures were alive. If we know what the ocean was like, we can guess what the climate was like. By studying shells from different periods, micropaleontologists can learn how the climate changed over time. 

History of Paleontology

People around the world have been uncovering fossils for thousands of years. They did not always understand what these objects were, though.

Paleontology, as we know it today, began in the 1700s. At that point, scientists carefully studied and classified fossils for the first time. In the 1850s, scientist Charles Darwin suggested that new species evolve over time. Over millions of years, a species can change and become a new species, Darwin said. Creatures today are related to different species from the distant past.

After learning about Darwin's theory of evolution, paleontologists began drawing connections between ancient fossils and living creatures. For example, paleontologists discovered that the prehistoric Archaeopteryx had wings like a bird. At the same time, it had the kind of teeth found in a type of dinosaur called theropods. Paleontologists concluded that the Archaeopteryx was a very early kind of bird. This was one of the first steps in the path from ancient dinosaurs to modern birds.

In the late 1800s, scientists discovered radioactivity. Radioactive objects send out a certain amount of energy over time. By measuring how much radioactive material a fossil has, scientists can guess the fossil's age. This is called radiometric dating

Paleontology Today

Now paleontologists use many advanced tools. Electron microscopes allow them to study the tiniest details of the smallest fossils. X-ray machines and CT scanners show the inside of fossils. Advanced computer programs can show whole skeletons. They can even show how extinct animals looked and moved.

Paleontologists still make discoveries with simple tools, too. Around the world, scientists are still digging away with pickaxes. Every paleontologist is hoping to shed new light on the evolution of life. 

 

Paleontology
Paleontologists dig deep.
abundant
Adjective

in large amounts.

Age of Enlightenment
Noun

(1700s) period in European history where science and reason were promoted as ideals of good citizens and society.

algae
Plural Noun

(singular: alga) diverse group of aquatic organisms, the largest of which are seaweeds.

amber
Noun

translucent, yellow-orange material made of the resin of ancient trees. Amber is sometimes considered a gemstone.

animal
Noun

organisms that have a well-defined shape and limited growth, can move voluntarily, acquire food and digest it internally, and can respond rapidly to stimuli.

appendage
Noun

part of something that extends out from the main body, such as an arm or leg.

aquatic
Adjective

having to do with water.

Archaeopteryx
Noun

extinct reptilian bird that lived about 150 million years ago.

arthropod
Noun

invertebrate animal with a segmented body, exoskeleton, and jointed appendages.

aspect
Noun

view or interpretation.

atmospheric changes
Noun

alterations in the layer of air surrounding the Earth, such as an increase of pollution or humidity.

atom
Noun

the basic unit of an element, composed of three major parts: electrons, protons, and neutrons.

Plural Noun

(singular: bacterium) single-celled organisms found in every ecosystem on Earth.

biblical
Adjective

having to do with the Bible, the holy book of Christianity.

biologist
Noun

scientist who studies living organisms.

biostratigraphy
Noun

study of the dating of rock layers.

catastrophe
Noun

disaster or sudden, violent change.

cell
Noun

smallest working part of a living organism.

Noun

(1809-1882) British naturalist.

Charles Lyell
Noun

(1797-1875) English geologist.

chemistry
Noun

study of the atoms and molecules that make up different substances.

Noun

complex way of life that developed as humans began to develop urban settlements.

classify
Verb

to identify or arrange by specific type or characteristic.

climate
Noun

all weather conditions for a given location over a period of time.

Noun

gradual changes in all the interconnected weather elements on our planet.

Noun

dark, solid fossil fuel mined from the earth.

coal ball
Noun

spherical structure of fossilized plant matter found in and around coal deposits.

colleague
Noun

a coworker or partner.

connective tissue
Noun

material that surrounds or links different organs or other parts of an organism.

Noun

one of the seven main land masses on Earth.

Noun

tiny ocean animal, some of which secrete calcium carbonate to form reefs.

Noun

rocky outermost layer of Earth or other planet.

crustacean
Noun

type of animal (an arthropod) with a hard shell and segmented body that usually lives in the water.

CT scanner
Noun

(computerized tomography scanner) device combining X-ray and computerized equipment to provide cross-sectional images of internal body structures. Also called a CAT scanner.

curative
Adjective

able to cure or treat a disease or illness.

cyanobacteria
Noun

type of aquatic bacteria that can photosynthesize light to create energy. Also called blue-green algae (even though it is not algae) and (in freshwater habitats) pond scum.

data
Plural Noun

(singular: datum) information collected during a scientific study.

debris
Noun

remains of something broken or destroyed; waste, or garbage.

decompose
Verb

to decay or break down.

deduce
Verb

to reach a conclusion based on clues or evidence.

Noun

area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.

dig site
Noun

place where paleontologists, archaeologists, or other scientists are digging into the Earth to find artifacts or fossils. Also called an excavation.

disprove
Verb

to prove wrong.

Noun

difference.

DNA
Noun

(deoxyribonucleic acid) molecule in every living organism that contains specific genetic information on that organism.

echinoderm
Noun

phylum of marine invertebrate including sea stars and sea urchins.

Noun

community and interactions of living and nonliving things in an area.

electron microscope
Noun

powerful device that uses electrons, not light, to magnify an image.

element
Noun

chemical that cannot be separated into simpler substances.

Emerging Explorer
Noun

an adventurer, scientist, innovator, or storyteller recognized by National Geographic for their visionary work while still early in their careers.

emit
Verb

to give off or send out.

environment
Noun

conditions that surround and influence an organism or community.

establish
Verb

to form or officially organize.

evolution
Noun

change in heritable traits of a population over time.

evolve
Verb

to develop new characteristics based on adaptation and natural selection.

excavation
Noun

area that has been dug up or exposed for study.

exoskeleton
Noun

the hard external shell or covering of some animals.

extinct
Adjective

no longer existing.

Noun

scientific studies done outside of a lab, classroom, or office.

flipper
Noun

large, flat limb used by marine mammals for swimming.

forest
Noun

ecosystem filled with trees and underbrush.

formulate
Verb

to develop or create.

Noun

remnant, impression, or trace of an ancient organism.

fossil fuel
Noun

coal, oil, or natural gas. Fossil fuels formed from the remains of ancient plants and animals.

fungi
Plural Noun

(singular: fungus) organisms that survive by decomposing and absorbing nutrients in organic material such as soil or dead organisms.

genetic
Adjective

having to do with genes, inherited characteristics or heredity.

Genyornis
Noun

extinct large, flightless bird indigenous to Australia.

geologist
Noun

person who studies the physical formations of the Earth.

Georges Cuvier
Noun

(1769-1832) French paleontologist and biologist.

Noun

mass of ice that moves slowly over land.

Gobi Desert
Noun

large desert in China and Mongolia.

hadrosaur
Noun

duck-billed dinosaur.

herd
Noun

group of animals.

hypothesis
Noun

statement or suggestion that explains certain questions about certain facts. A hypothesis is tested to determine if it is accurate.

ice age
Noun

long period of cold climate where glaciers cover large parts of the Earth. The last ice age peaked about 20,000 years ago. Also called glacial age.

indicator
Noun

sign or signal.

invertebrate
Noun

animal without a spine.

invertebrate paleontology
Noun

study of the fossils of animals without spines, such as corals, sponges, and insects.

isolate
Verb

to set one thing or organism apart from others.

lung
Noun

organ in an animal that is necessary for breathing.

mammal
Noun

animal with hair that gives birth to live offspring. Female mammals produce milk to feed their offspring.

mammoth
Noun

one of many extinct species of large animals related to elephants, with long, curved tusks. The last mammoths became extinct about 5,000 years ago.

marine
Adjective

having to do with the ocean.

microfossil
Noun

fossil that can only be seen and analyzed with a microscope, such as a grain of pollen or a single bacterium.

microorganism
Noun

very tiny living thing.

micropaleontology
Noun

study of fossils of microorganisms.

Middle Ages
Noun

(500-1500) period in European history between the Roman Empire and the Renaissance.

mold
Noun

type of fungi that forms on the surface of materials.

mollusk
Noun

large phylum of invertebrate animal, all possessing a mantle with a significant cavity used for breathing and excretion, a radula (except for bivalves), and the structure of the nervous system. 

myth
Noun

legend or traditional story.

National Geographic Society
Noun

(1888) organization whose mission is "Inspiring people to care about the planet."

nest
Noun

protected area built by birds to hatch their eggs and raise their young.

Noah's flood
Noun

story in the Bible, a catastrophe that eliminated almost all life on Earth.

Noun

substance an organism needs for energy, growth, and life.

oyster
Noun

type of marine animal (mollusk).

paleobotany
Noun

study of the fossils of ancient plants.

Noun

study of the atmosphere of prehistoric Earth.

paleoecology
Noun

study of prehistoric environments and habitats.

paleontologist
Noun

person who studies fossils and life from early geologic periods.

Noun

the study of fossils and life from early geologic periods.

Patagonia
Noun

large plateau in southern South America, stretching from the Andes Mountains to the Atlantic Ocean.

petrify
Verb

to turn to stone.

pioneer
Noun

person who is among the first to do something.

plant
Noun

organism that produces its own food through photosynthesis and whose cells have walls.

pollen
Noun

powdery material produced by plants, each grain of which contains a male gamete capable of fertilizing a female ovule.

prehistoric
Adjective

period of time that occurred before the invention of written records.

prior
Adjective

before or ahead of.

protist
Noun

type of microscopic organism (not an animal, plant, or fungus). 

pterosaur
Noun

extinct order of flying reptiles that flourished from 220 million-65 million years ago.

Quetzalcoatlus
Noun

flying reptile that lived about 70 million years ago, native to North America.

radioactive
Adjective

having unstable atomic nuclei and emitting subatomic particles and radiation.

radiometric dating
Noun

method of dating material such as rocks that compares the amount of a naturally occuring isotope of an atom and its decay rates. Also called radioactive dating.

resin
Noun

clear, sticky substance produced by some plants.

revolutionize
Verb

to completely change a process or way of doing something.

root
Noun

part of a plant that secures it in the soil, obtains water and nutrients, and often stores food made by leaves.

scholar
Noun

educated person.

seafloor
Noun

surface layer of the bottom of the ocean.

Noun

solid material transported and deposited by water, ice, and wind.

sequence
Verb

to put in order.

Shen Kuo
Noun

(1031-1095) Chinese scientist, politician, and poet.

Siberia
Noun

region of land stretching across Russia from the Ural Mountains to the Pacific Ocean.

skeleton
Noun

bones of a body.

soft tissue
Noun

connective tissue of an organism, such as blood, muscle, and skin.

specimen
Noun

individual organism that is a typical example of its classification.

sponge
Noun

simple type of marine animal permanently attached to something in the water.

stromatolite
Noun

fossil of ancient cyanobacteria that forms a rounded or column-like structure.

subdiscipline
Noun

field of study within a larger area of research.

suffocate
Verb

to be unable to breathe.

sustain
Verb

to support.

Noun

land permanently saturated with water and sometimes covered with it.

technology
Noun

the science of using tools and complex machines to make human life easier or more profitable.

theropod
Noun

type of dinosaur that walked on two legs and was usually carnivorous.

T. rex
Noun

(Tyrannosaurus rex) large carnivorous or scavenger dinosaur.

unearth
Verb

to dig up.

vertebrate
Noun

organism with a backbone or spine.

vertebrate paleontology
Noun

study of the fossils of animals with spines, such as dinosaurs.

volcanic eruption
Noun

activity that includes a discharge of gas, ash, or lava from a volcano.

William Smith
Noun

(1769-1839) English geologist.

wingspan
Noun

the distance between the tips of a bird's wings when stretched out.

worm
Noun

animal with a long, limbless body.

Xenophanes
Noun

(570-480 BCE) Greek philosopher and poet.